Measuring various atmospheric parameters and transmitting these parameters to a remotely located receiver by means of an atmospheric sounding device is well known in the art. The atmospheric sounding device (ASD) includes an instrumental box and a balloon filled with a gas lighter than air. The balloon is connected with the instrumental box or other payload through a connecting element in the form of a string. The string may include a parachute to provide for a safe landing of the payload after the balloon is destroyed high in the atmosphere.
Currently, aerological sounding is performed under light and moderate surface winds having the speed up to 12 m/s. A standard aerological station has a shelter protecting an operator from the strong wind and precipitation while the operator is filling the balloon with a gas. However, the launch of the sounding device is performed outside of the shelter, in the open. Specifically, launching the sounding device requires the operator to hold and operate the balloon and the instrumental box with his hands. Thus, launching the sounding device under strong (12-20 m/s) winds is a complex and sometimes dangerous procedure for the operator. In addition, when the launch takes place under strong surface wind, the sounding device may hit the ground and experience fatal damages.
Strong winds often occur in polar and subpolar regions, in coastal areas, and in areas with tropical cyclones. Since the launch of the sounding device from a ground-based station in a tropical cyclone area is almost impossible, dropsondes dumped from costly reconnaissance aircrafts are used to measure meteorological parameters.
To mitigate the impact of weather conditions during the launch of the sounding device, it is known to use a temporary string length regulator, hereinafter referred to as a dereeler. The dereeler is embedded into the string, between a parachute and the instrumental box, and includes additional coiled string. However, the application of the dereeler substantially complicates the launch preparation, and increases cost and weight of the sounding device. Specifically, the string in the dereeler often gets entangled or jammed as result of wind gusts. The usage of the dereeler does not protect the operator from strong winds.
Shelters having a sliding roof with a wind deflector are known and used in the art for launching sounding devices. Specifically, the sounding device is released from a shelter through an opening (hatch) in the sliding roof. However, while passing through the opening under strong winds, the balloon string, equipped with a parachute, a dereeler, and an instrumental box, often gets hooked by a ledge of an exhaust outlet of the shelter resulting in damages to the instrumental box.
A wind deflector mounted along the perimeter of the roof is disclosed in U.S. Pat. No. 5,636,480 to Lauristen et al. However, the deflector does not reduce the horizontal component of the wind speed above the open roof. As such, the method of Lauristen et al. is limited to protecting the balloon while it gets inflated, but does not enable safe pass of the sounding device through the opening under strong surface winds.
Accordingly, there is a need for a method and facility to enable the launch of an atmospheric sounding device under strong surface winds whereby avoiding potential damages to the instrumental box and protecting the operator from the strong winds. Specifically, the method and facility are needed to prevent the sounding device from hitting the ground during the launch. When a shelter is used for launching the sounding device, the method and facility are needed to prevent the string and other elements of the sounding device from getting hooked by the ledge of the opening in the sliding roof.